The present invention relates to a herbicidal composition comprising a derivative of 1,2,4-triazole as an active ingredient, represented by the general formula (I): ##STR3## wherein R.sup.1 represents a hydrogen atom, a halogen atom or a (C.sub.1 -C.sub.2) alkyl group; R.sup.2 represents a hydrogen atom, a halogen atom, a (C.sub.1 -C.sub.2) alkyl group, fluoromethyl group (--CH.sub.2 F), 3,3,3-trifluoropropyl group, methoxy group, cyano group, methoxymethyl group, methylthio group, methoxycarbonyl group or isopropoxycarbonyl group and R.sup.3 represents a thiocarbamoyl group or a group represented by the general formula (II): ##STR4## wherein R.sup.4 represents a hydrogen atom, a (C.sub.1 -C.sub.2) alkyl group or a hydroxy (C.sub.1 -C.sub.2) alkyl group and R.sup.5 represents a hydrogen atom, a (C.sub.1 -C.sub.2) alkyl group, halogeno (C.sub.1 -C.sub.2) alkyl group, hydroxy (C.sub.1 -C.sub.2) alkyl group, cyanomethyl group, acetyl group, halogenoacetyl group, methoxyacetyl group, amino group, phenyl group, methoxy group, hydroxyl group, (C.sub.2 -C.sub.3) alkenyl group, halogeno (C.sub.2 -C.sub.3) alkenyl group, isopropylcarbonyl group, methylthiocarbamoyl group or 2-methoxyethyl group, with the proviso that R.sup.2 is not a hydrogen atom, halogen atom or (C.sub.1 -C.sub.2) alkyl group when both of R.sup.4 and R.sup.5 represent hydrogen atoms, and herbicidally acceptable carrier(s) or diluent(s).
The present inventors have studied for finding a compound showing an excellent activity in selectively controlling weeds such as Echinochloa crus-galli, Poa annua, Chenopodium album, Cardamine flexuosa, Portulaca orelacea, etc. without any phytotoxicity to crop plants such as rice, wheat and maize, and as a result, they have found that a derivative of 1,2,4-triazole, represented by the general formula(I) shows an excellent herbicidal activity for practically controlling the weeds, and have been attained to the present invention.